Conventionally, in various types of printers, a printing member is loaded on and held by a supplying unit (such as a paper core and a ribbon core) for a printing member, such as printing paper or an ink ribbon and a thermal transfer ribbon. The printing member is held basically in one of the following manners: both-end supporting in which the core is supported at its both ends and the printing member is held therebetween, or one-end supporting in which the core is supported by only one end and the printing member is held by the supported end.
Further, methods of aligning the printing member across a width direction along a transfer path include a center alignment method for aligning the printing member in the center of the transfer path. This is often employed in both-end supporting and in a one-end alignment method for aligning the printing member on one end of the transfer path and is often employed in the one-end supporting.
In the both-end supporting, as the printing paper or the ribbon is centered, print heads such as a thermal head and the like in a printing unit are balanced on right and left, and a transfer resistance of the printing member is also balanced. This provides an advantage that wrinkling and meandering would not be likely to occur, especially in the case of thin thermal transfer ribbons. However, as the structure is complicated, there are problems of inconvenience in assembly and increased cost, and a problem that loading of the printing member becomes cumbersome.
On the other hand, in the one-end supporting, as the printing paper or the ribbon is aligned on one end, the print head in the printing unit is relatively unbalanced on the right and left, and the transfer resistance of the printing member is also relatively unbalanced. This provides an adverse effect that wrinkling and meandering could easily occur, especially in the case of thin thermal transfer ribbons. However, due to the simple structure, there are advantages that the assembly is facilitated, the cost is reduced, and the printing member can be loaded in a relatively simple manner.
As described above, both methods of aligning the printing member by both-end supporting and one-end supporting have, in connection with the center alignment and the one-end alignment, have advantages and disadvantages in their performance and cost. Many printers employ the one-end supporting aligning method considering many features, mainly the structure and cost.
However, taking the compatibility of printing data that a printer user has used in the past into account, a user who has been using a printer with one-end supporting or one-end alignment will have to select a printer of the structure of one-end supporting or one-end alignment under relatively poor conditions, such as the imbalance of the print head on the right and left or the transfer resistance, unless the user changes a processing method of the printing data to a processing method for both-end alignment (that is, unless the user changes the processing method so as to change a portion used by the print head) when using a printer with both-end supporting.
Conversely, when a user, who has been using a printer of center alignment and has been using the both-end supporting, later replaces the printer of both-end supporting with a printer of one-end alignment, the user is adversely required to convert printing data that has been processed to be printed using a central region of the print head in accordance with the one-end alignment so as to change the used portion of the print head to a large extent.
Therefore, after starting to use a printer of one-end alignment, if the user creates new printing data and uses the printer based on the printing data, the user has to continue using the printer of one-end alignment having the above problems unless entirely converting the printing data into data in accordance with the center alignment.
It should be noted that recognizing a width of a printing member when it is set on the supplying unit is necessary not only to detect erroneous setting of the printing member of a different width, but also to control the print processing using the printing member. Thus, there is a demand for providing ability for recognizing a width of the printing member that is set on the supplying unit.